Temperature-water-plant-soil coupled modelling for slurry optimization in agricultural soils as a nature-based solution for flooding management
(NERC CASE studentship, DTP)
Dr Xiaohui Chen (Leeds, School of Civil Engineering), Dr Ana Heitor (Leeds, School of Civil Engineering), Dr Nick Humphries (N2-Applied), Professor Joe Holden (Leeds, School of Geography)
Background: Increased rainfall frequency and flooding are attributed to climate change (Blöschl et al., 2017, Kundzewicz et al., 2014; Hirabayashi and Kanae, 2009). As flood risk is a major challenge for society, a twin-track approach with hard engineering and natural flood management is now being pursued in many countries. Very little is known about the role of soil management in natural flood management strategies. In agricultural landscapes slurry has been widely used for improving soil functioning in terms of holding more water and nutrients for plants (Figure 1). Use of slurry is important as it enables a waste product to be harnessed for food production in a world where raw materials for fertilisers are running short. However, optimization of slurry application and design for agricultural soils to help them buffer against flooding and droughts remains a challenge.
Figure 1: Slurry on a farm (naturalengland)
Farm soils upstream of rivers may have a direct impact on flooding as they could slow water flow if soil and vegetation conditions are suitable, and they may even release water during droughts. However, some types of farm management may exacerbate flood risk downstream. It is therefore important to establish techniques that could be adopted on farms to manage water storage and flow rates, and reduce downstream flood risk.
Aim: This project seeks to develop a slurry system that provides good performance for crops but also aids flood management provided by farms to the wider landscape. It will investigate the influence of coupled roots-microbes-slurry functioning on nutrients transport (N2), and the physical properties of soils (e.g. permeability, macropores, stability) under extreme weather conditions.
Methods: This project will combine field experiments at the University of Leeds farm, and numerical modelling. Field analysis will examine how different slurry applications influence soil functions including water holding capacity, infiltration, permeability, and nutrient uptake. Interactions between water, soils, crops, and slurry will be studied and the project will develop a novel theoretical model along with 3-D computational modelling, supported by the field experimental data.
Potential for high impact outcome
Despite the large number of studies looking at flooding management, very few studies have linked water, soils, slurry and plant coupled performance analysis. The model developed will have a potentially wide influence in terms of sustainable agriculture management and nature-based solutions investment under environmental stewardship schemes. The direct engagement with industry and with farmer networks will enhance the knowledge transfer to maximise the impact of this study. The research is expected to be published in top international journals of environmental science such as ES&T
You will work under the supervision of a cross-disciplinary team of modelling and experimental experts across the School of Civil Engineering and the School of Geography, and directly engage with the company N2-Applied. Supervision will be provided by Dr. Xiaohui Chen (Modelling), Dr Ana Heitor (Experiment), Professor Joe Holden (Flooding), and industry supervisor Dr Nick Humphries (Chief Agronomist). The School of Civil Engineering and School of Geography has state-of-the-art laboratory facilities. You will have access to the University of Leeds commercially-run farm which is undergoing considerable investment in instrumentation and can be trained in agricultural practice. You will have access to a broad spectrum of training as required including numerical modelling, soil hydrology and more generic skills-based training (http://www.emeskillstraining.leeds.ac.uk/).
You are expected to have strong interests in modelling and field experiments. You also should have some background in disciplines such as mathematics, physics, geography, biology, or environmental science. Strong analytical skills are required.
Blöschl, J. Hall, J. Parajka, R.A. Perdigão, B. Merz, B. Arheimer, G.T. Aronica, A. Bilibashi, O. Bonacci, M. Borga, I. Čanjevac (2017) Changing climate shifts timing of European floods Science, 357, pp. 588-590
Hirabayashi, R. Mahendran, S. Koirala, L. Konoshima, D. Yamazaki, S. Watanabe, H. Kim, S. Kanae Y. Hirabayashi, S. Kanae (2009) First estimate of the future global population at risk of flooding Hydrological Research Letters, 3, pp. 6-9.
Kundzewicz, Z.W., Kanae, S., Seneviratne, S.I., Handmer, J., Nicholls, N., Peduzzi, P., Mechler, R., Bouwer, L.M., Arnell, N., Mach, K, Muir-Wood, R. (2014). Flood Risk and Climate Change: Global and Regional Perspectives. Hydrological Sciences Journal 59, 1 – 28.